package com.lagou.edu.jdbc;

import com.lagou.edu.annotation.Component;
import com.lagou.edu.config.ApplicationConfig;

import java.sql.Connection;
import java.sql.SQLException;

/**
 * @author fanbo@imoran.net
 * @date 2020/12/25 下午8:20
 */

@Component
public class ConnectionUtils {
    /**
     * 存储当前线程的连接
     */
    private ThreadLocal<Connection> threadLocal = new ThreadLocal<>();

    /**
     * 从当前线程获取连接
     */
    public Connection getCurrentThreadConn() throws SQLException {
        /**
         * 判断当前线程中是否已经绑定连接，如果没有绑定，需要从连接池获取一个连接绑定到当前线程
         */
        Connection connection = threadLocal.get();
        if(connection == null) {
            /** 从连接池拿连接并绑定到线程 */
            connection = ApplicationConfig.druidDataSource.getConnection();
            /** 绑定到当前线程 */
            threadLocal.set(connection);
        }
        return connection;

    }
}
